This application claims the priority benefit of Taiwan application serial no. 88122875, filed Dec. 24, 1999.
1. Field of the Invention
The invention relates to a micro-retarder plate, and more particular, to a micro-retarder plate using only a single layer of retardation material that can be applied in a three-dimensional stereo imaging and display system.
2. Description of the Related Art
Processing a polarizer or a phase retarder to obtain a pattern thereon, and applying the patterned polarizer or phase retarder to a liquid crystal display screen, a three-dimensional stereo imaging can thus be provided for audience wearing a pair of polarization glasses. In U.S. Pat. No. 5,327,285, the fabrication method performed on a micro polarizer includes ink printing and photolithography. U.S. Pat. No. 5,844,717 also discloses using method of etching photoresist to fabricate micro-polarizer.
In the above prior arts U.S. Pat. No. 5,327,285 and U.S. Pat. No. 5,844,717, as shown in FIG. 1A to FIG. 1C, two polarizers 102 and 104 processed with polarization directions vertical to each other are required. By laminating these two polarizers and alternating the patterns thereof, an observer wearing a pair of glasses can see a three dimensional image using this lamination 106. For example, as shown in FIG. 1C, lamination 106 of micro-polarizer is disposed in front of a liquid crystal display 108 that comprises left-eye vision areas and right-eye vision area alternating with each other. As shown in FIG. 1C, aligning with the liquid crystal display 108, two polarization directions 112 are alternating each other corresponsive with the left- and right-eye vision areas. An observer wearing a pair of glass 110 can thus see a three-dimensional image. However, as the patterns on the polarizers are typically very small in dimension, so that it is very difficult to aligning two patterns exactly alternating to each other. While misalignment occurs, it is easily to cause a double image that seriously affects the stereo effect. In addition, using the micro-polarizer reduces the incident light into less than a half in intensity since double layer micro-polarizers are used. Therefore, the brightness of the image is very often a problem for such a display system.
The invention provides a micro-retarder plate, comprising a single plate with phase retardation. The plate with phase retardation comprises a pattern that further comprises a plurality of first retardation state areas and a plurality of second retardation state areas alternating with each other. The pattern is formed using an infra-red laser to expose the plate with phase retardation, or using a circuit board with a pattern of electrothermal resistor thereon in contact with the plate of phase retardation. The micro-retarder is laminated between two transparent layers for index-matching. The transparent layers can further be laminated with two protection layers.
Thus formed, only a single plate with phase retardation is required, so that the material consumption is greatly reduced. Using only a single plate of retardation material to form the micro-retarder, the alignment of the areas between two polarizers with different polarization state is no longer required and thus the double image caused by misalignment is prevented. Furthermore, the brightness of the light passing through the micro-retarder using single plate can be maintained. In addition, without using the conventional chemical process, the environment pollution can also be prevented.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.